Embodiments of the present invention relates to a light emitting diode (LED) package and a RFID system; and particularly, to a RFID tag configured to communicate with an external reader by transmitting and receiving a wireless signal to control an LED package.
A Radio Frequency Identification (RFID) is a type of communication method which provides contactless identification by using a RFID chip attached to a target for identification and a RFID reader configured to transmit a wireless signal with the RFID chip. The RFID can make improvements on conventional optical character recognition technology as well as advance a conventional automatic identification system such as a bar code system.
Recently, a RFID system may be used in a distribution system (logistics), an access authentication system, an electronic payment system, an access card system used in transportations and securities, and so on.
For example, for logistics an integrated circuit (IC) chip including identification information can be used for inventory control and classification instead of a delivery sheet, slip or chip. In the access authentication system, entry to an office or a system is determined by an IC card including personal information.
An RFID device stores data within a memory, particularly the RFID chip may comprise a nonvolatile ferroelectric memory configured to store information.
The data processing speed of nonvolatile ferroelectric memory (i.e., Ferroelectric Random Access Memory (FeRAM)) is typically similar to that of Dynamic Random Access Memory (DRAM). However, FeRAM is different than DRAM, in that data stored in FeRAM is retained even when power to the memory device is turned off. Thus, FeRAM has been receiving a lot of attention and is considered a strong candidate as a next generation memory device.
The structure of FeRAM is similar to that of DRAM in that FeRAM includes a plurality of capacitors. However, the capacitors in a FeRAM device are made of a ferroelectric material having a high residual polarization, which in turn allows for data retention even when the power supplied to the memory device is terminated.
FIG. 1 is a block diagram describing a conventional RFID system. As shown, the conventional RFID system includes an antenna unit 1, an analog processing unit 10, a digital processing unit 20, and an information storing unit 30.
Herein, the antenna unit 1 is for receiving a wireless signal transmitted from an external RFID reader. The wireless signal received through the antenna unit 1 is passed through antenna pads 11 and 12 and inputted to the analog processing unit 10.
The analog processing unit 10 amplifies the wireless signal to generate a power voltage VDD used as a power source for the RFID chip, and extracts a command signal from the wireless signal to output the command signal into the digital processing unit 20. Also, the analog processing unit 10 outputs a power-on-reset signal POR (for controlling a reset operation in response to the power voltage VDD) and a clock signal CLK to the digital processing unit 20.
The digital processing unit 20 receives the power voltage VDD, the power-on-reset signal POR, the clock signal CLK, and the command signal CMD, and generates a response signal RP that is provided to the analog processing unit 10. Additionally, the digital processing unit 20 provides an address ADD, an input/output data I/O, a control signal CTR, and the clock signal CLK to the information storing unit 30.
The information storing unit 30 reads or writes the input/output data I/O at a location corresponding to the address ADD and retains the data even after the power is turned off.
The RFID system operates in various frequency-bands, but operating capabilities of the RFID system can be changed according to a different frequency-band. As the RFID system operates in a lower frequency-band, a recognition speed becomes slower and an operation range becomes smaller, but a recognition rate is less influenced by external environments. Otherwise, if the RFID system operates in a higher frequency-band, a recognition speed becomes faster and an operation range becomes broader, but a recognition rate is more influenced by external environments.